Method for producing packaged drink

ABSTRACT

It is intended to provide a process for producing a packaged drink whereby filling can be performed at room temperature without resorting to using a chemical or sterile water, the favorable taste and flavor of the content can be maintained while relieving the thermal degradation thereof, it becomes unnecessary to employ a heat-resistant container or to thermally sterilize or cool after sealing, and thus both of the equipment cost and the running cost can be largely reduced. After thermally sterilizing the content to give a definite sterilization value, it is quickly cooled to room temperature and then stored in a storage tank that has been preliminarily sterilized under such conditions as being equal to or exceeding the thermal sterilization conditions for the contents. While maintaining the storage tank under positive pressure with the use of a sterile gas, the content is fed into a filling machine that has been preliminarily sterilized under such conditions as being equal to or exceeding the thermal sterilization conditions for the contents. Thus, the liquid-feeding system ranging from the storage tank to the filling machine is made a closed liquid-feeding pathway free from the invasion of air from the outside. The drink is filled into a container having been sterilized with hot water in an environment-controlled space isolated from the outside wherein the surroundings have been thermally sterilized and washed with hot water at 65° C. to 100° C.

TECHNICAL FIELD

The present invention relates to a method for producing a packageddrink, in particular a packaged drink such as a packaged tea drink and apackaged acidic drink.

BACKGROUND

Hot pack methods and aseptic methods are conventionally known methodsfor producing packaged drinks of low acidic drinks such as green teadrinks or the like, or acidic drinks such as drinks with fruit juice orthe like that are packaged in, for instance, PET bottles. In hot packmethods, the drink, for instance is thermally sterilized at conditionsequal to or exceeding 120° C. and 4 minutes, for low acidic drinkshaving a pH of 4.6 or higher such as tea drink or the like, andconditions equal to or exceeding 85° C. and 30 minutes for acidic drinkshaving a pH of 4.6 or lower, the content being then filled, with theliquid temperature kept at 65° C. to 90° C., into washed containers thatare then sealed, the containers being sterilized herein by the heat ofthe content. Thereafter, to sterilize the head space of the containersand the inner surface of the caps, the containers are turned upside downimmediately after sealing, and the cap inner surface and so forth aresterilized by coming into contact with the liquid, in what is calledoverturning sterilization. Simultaneously therewith, hot water issprayed onto the outer peripheral face of the containers in apasteurizer, to carry out thereby thermal sterilization at 75° C. over 3minutes. Thereafter, the containers are cooled down to room temperature(see Patent document 1 for an example of this method).

Hot pack methods are highly problematic in that the content is kept at ahigh temperature, of 60° C. or above, over a long time, with the contentbeing filled in that state. As a result, the content may undergo thermaldeterioration, which may result in rapid loss of taste and flavor.Moreover, the surface of the container is brought into contact with thehigh-temperature drink during filling, and hence the containers must beheat-resistant, which necessitates a heat resistance treatment in thecase of, for instance, PET bottles. Moreover, negative pressure developsin the interior of the containers after cooling, and thus the containersmust be made thick-walled so as to ensure sufficient strength towithstand that negative pressure. The foregoing drives up thus the costof the containers, which is a drawback. In terms of equipment, hot packmethods suffer the drawback of increased equipment space and higherequipment costs brought about by the need for large-scale pasteurizersfor post-sterilization and cooling. From the viewpoint of running costs,pasteurizers are also problematic in that they require large amounts hotwater, which entails greater water consumption and higher energy costs.

In aseptic filling, meanwhile, the drink, which has been sterilizedbeforehand at high temperature for a short time using a means such as aheat exchanger or the like, followed by cooling, is sterilized with achemical agent such as hydrogen peroxide, peracetic acid or the like.The drink is filled and sealed then, at room temperature and in anaseptic environment, into containers which need not be heat resistantand that have been washed with aseptic water. This method can ensuresealing in wholly aseptic conditions, and hence the method is adequatefor filling, even at room temperature, not only acidic drinks or tea butalso milk-containing drinks in which spore-forming bacteria, such asClostridium botulinum or the like, proliferate readily. Although asepticfilling is thus advantageous in that it entails little thermaldeterioration of contents, it requires a sterilizing chemical agent anda chemical agent treatment device for sterilizing the containers.Aseptic filling requires also, for instance, large amounts of asepticwater and a washing device for washing the containers. Aseptic fillingis thus a large-scale operation involving various equipment for carryingout the above steps, as well as a clean room and ancillary controls. Themethod is hence problematic in terms of the substantial equipment costand running costs associated therewith.

Therefore, the inventors proposed (Patent document 2) a novel hot packmethod as a method for solving the above problems of conventional hotpack methods and aseptic filling methods. This novel method involvedthermally sterilizing a green tea drink comprising 30 mg % or more ofcatechins at a pH of 4.6 or higher or an acidic drink having a pH below4.6; keeping thereafter the drink at a temperature of 60° C. to 70° C.;thermally sterilizing and washing at least the inner surface of acontainer with worm water at 65° C. to 100° C.; filling the drink intothe sterilized container, at a filling temperature of 60° C. to 70° C.,in an environment-controlled space, isolated from the outside, in whichthe filling and sealing devices and the surrounding environment thereofare thermally sterilized and washed beforehand with worm water at 65° C.to 100° C.; and cooling, after sealing, down to room temperature nothigher than 40° C.

This method does not require a post-sterilization step after filling andsealing, and hence no large-scale equipment in the form of pasteurizersneed be employed. The method is advantageous in allowing reducingequipment costs and running costs as compared with conventional hot packmethods, and in allowing easing the conditions relating to containerresistance against vacuum deformation. The method, however, isproblematic in that it requires a cooling step after sealing, andresults in loss of taste and/or flavor, brought about by content thermaldeterioration, although to a lesser extent than in conventional hot packmethods. Also, the method cannot obviate the need for the containers tobe resistant to vacuum deformation.

Patent document 1: Japanese Unexamined Patent Application Laid-open No.2001-278225 “Producing method of beverage bottle”, Oct. 10, 2001

Patent document 2: Japanese Unexamined Patent Application Laid-open No.2006-69624 “Method for producing a packaged drink”, Mar. 16, 2006

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

Lowering the filling temperature is an effective way of solving theabove-described shortcomings of conventional hot pack methods. Once thecontent is cooled to room temperature after sterilization, however,microbial contamination remains a possibility on account of small partssuch as liquid-feeding pumps, packings, joints and so forth, in theliquid-feeding system from the storage tank to the filling machine, thatare ordinarily used in filling equipment, while from the viewpoint ofproduct safety, it has not been possible heretofore to lower the fillingtemperature below that in the above-described prior art documents.

With a view to further improving the proposed filling systems above, itis an object of the present invention to provide a method for producinga packaged drink, comprising a novel filling and sealing system, thatpermits room temperature filling and allows maintaining good taste andflavor by mitigating thermal deterioration of the content, that does notrequire using a heat-resistant container, that does not require thermalsterilization or cooling after sealing, and that does not require usinga chemical agent or sterile water, as in aseptic filling methods, toafford as a result substantial savings in equipment costs and runningcosts.

It is a further object of the present invention to provide a method forproducing a packaged drink, comprising a novel filling and sealingsystem, that permits room temperature filling and allows maintaininggood taste and flavor by mitigating thermal deterioration of thecontent, that does not require using a heat-resistant container, thatdoes not require thermal sterilization or cooling after sealing, andthat does not require using a chemical agent or large amounts of sterilewater, as in aseptic filling methods, to afford as a result substantialsavings in equipment costs and running costs.

Means for Solving the Problems

In order to attain the above goal, and as a result of diligent researchand experimentation, the inventors perfected the present invention uponfinding that content sterilization by chemical agent becomesunnecessary, and that the content can be filled at room temperaturethrough quick cooling after quick thermal sterilization, by restrictingthe content drink to drinks in which growth of spore-forming bacteria isdifficult after heating, for instance a tea drink such as Oolong tea orgreen tea comprising 30 mg % or more of catechins at a pH of 4.6 orhigher, and an acidic drink having a pH below 4.6, and upon finding thatcontent sterilization by chemical agent becomes unnecessary, and thatthe content can be filled at room temperature through quick coolingafter quick thermal sterilization, by making the liquid-feeding pathwayof the content liquid, from thermal sterilization of the content tofilling thereof, into a sterilized wholly closed space, and bymaintaining a clean environment, isolated from the outside, in whichcontainers and the filling and sealing environment are sterilized withworm water.

Specifically, the method for producing a packaged drink of the presentinvention, which achieves the above goal, comprises the steps ofthermally sterilizing and washing beforehand, using worm water at 65° C.to 100° C. or a chemical agent, a surrounding environment where acontainer and a cap are sterilized, washed, filled and sealed; thermallysterilizing and washing beforehand a liquid-feeding pathway, up to acooling device, a storage tank and a filling machine, under conditionsequal to or exceeding the thermal sterilization conditions of a drink tobe filled; and thermally sterilizing and washing at least the innersurface of the container and cap with hot water at 65° C. to 100° C.,wherein the drink to be filled is thermally sterilized up to apredetermined sterilization value and is thereafter quickly cooled toroom temperature, the cooled drink being stored in the storage tank, andwherein a content liquid is fed to the filling machine to make theliquid-feeding pathway into a closed liquid-feeding pathway into whichouter air does not intrude, and the surrounding environment is made anenvironment-controlled space isolated from the outside, such that thedrink is filled at room temperature into the sterilized container andthen sealed in the environment-controlled space.

Another invention of the present application is the above method forproducing a packaged drink, wherein the drink is a drink comprising 30mg % or more of catechins at a pH of 4.6 or higher, and the drink isthermally sterilized to a sterilization value equal to or higher thanthat of thermal sterilization at 135° C. and 7.58 seconds.

Another invention of the present application is the above method forproducing a packaged drink, wherein the drink is an acidic drink havinga pH below 4.6, and the drink is thermally sterilized to a sterilizationvalue equal to or higher than that of thermal sterilization at 85° C.and 30 minutes.

Another invention of the present application is any of the above methodsfor producing a packaged drink, wherein the environment-controlled spaceis a space housed in a box.

A further invention of the present application is characterized in thatthe storage tank is kept at positive pressure with sterile gas, and theliquid is fed from the storage tank to the filling machine throughpressure-feeding by sterile gas.

Another invention of the present application is the above method forproducing a packaged drink, wherein washing which is performed afterthermal sterilization and washing of the surrounding environment using achemical agent has also a sterilizing function by using hot water at 65°C. to 100° C.

Another invention of the present application is the above method forproducing a packaged drink, wherein any of a peracetic acid chemicalagent, hydrogen peroxide, an ozone-based chemical agent, and achlorine-based disinfectant containing hypochlorous acid is used as thechemical agent for sterilizing and washing beforehand the surroundingenvironment where a container and a cap are sterilized, washed, filledand sealed.

EFFECTS OF THE INVENTION

The method for producing a packaged drink of the present inventionenables room-temperature filling of, for instance, acidic drinks such asfruit juice drinks, as well as tea- or milk-containing drinks or thelike, without the need for containers, equipment and the environment tobe sterilized with a chemical agent solution or washed with sterilewater, as is the case in aseptic filling methods. The invention allowsthus obtaining a good packaged drink, as afforded by aseptic fillingmethods, without flavor loss due to content thermal deterioration, whichoccurs in hot pack methods. The method of the present invention,moreover, resorts to simpler equipment than aseptic filling, and uses nochemical agent solution. Hence, the method of the present inventionaffords substantial savings in equipment costs and running costs whileincreasing the efficiency and speed of the production line. In themethod of the present invention, the containers need not beheat-resistant or resistant to vacuum deformation, and thus the walls ofthe containers may be thinner, which allows reducing container costs.The method of the present invention, moreover, requires nopost-sterilization or cooling after sealing, and hence equipment issimpler than in hot pack methods. The method of the present inventionrequires no large amounts hot water, and allows thus reducing equipmentand running costs while increasing line speed. The products, moreover,can move onto inspection, box packing and so forth immediately afterfilling and sealing, which allows increasing line efficiency whileachieving energy savings.

In the method for producing a packaged drink of the present invention,in which a surrounding environment is thermally sterilized and washedusing a chemical agent, the use of chemical agent is restricted, in thecase of acidic drinks such as fruit juice drinks, as well as tea- ormilk-containing drinks or the like, to the step of sterilizing andwashing the surrounding environment, in which the containers are washed,filled and sealed, that is carried out prior to filling. Hence, roomtemperature filling becomes possible without the need for large amountsof chemical agent solution, sterile water and so forth, as is the casein aseptic filling. The method of the present invention allows thusobtaining a good packaged drink, as afforded by aseptic filling methods,with little flavor loss due to content thermal deterioration, whichoccurs in hot pack methods.

Also, less chemical agent and washing liquid need be used, compared toaseptic filling, and hence equipment can be scaled down in proportion.The method of the present invention, moreover, requires nopost-sterilization or cooling after sealing, and hence equipment issimpler than in hot pack methods. This affords, as a result, substantialsavings in equipment costs and running costs.

In the method for producing a packaged drink of the present invention,the drink is thermally sterilized to a sterilization value equal to orhigher than that of thermal sterilization at 135° C. and 7.58 seconds,when the drink is a drink comprising 30 mg % or more of catechins at apH of 4.6 or higher. However, the drink is quickly cooled down to roomtemperature after sterilization, and therefore, the method of thepresent invention allows mitigating thermal deterioration and preservingflavor, in addition to the above effects. In a tea drink comprising 30mg % or more of catechins at a pH of 4.6 or higher, the environmentafter filling and sealing is an environment where spore-forming bacteriacannot survive, and hence sterilizing and washing the containers withhot water prior to drink filling does away with the need forsterilization after filling using a pasteurizer.

When in the method for producing a packaged drink of the presentinvention the drink is an acidic drink having a pH below 4.6, thermallysterilizing the acidic drink to a sterilization value identical to orhigher than 85° C. and 30 minutes allows inhibiting bacterial growthafter sealing, besides the above effects. Also, the drink is quicklycooled after thermal sterilization, which allows preventing flavor andcomponent deterioration. Moreover, sterilizing and washing the containerwith hot water prior to drink filling does away with the need forsterilization after filling using a pasteurizer.

In the method for producing a packaged drink of the present invention,besides the above effects, making the environment-controlled space wherethe containers are sterilized with hot water, the content is filled andthe containers are sealed, into a space housed in a box, has the effectof isolating that space from the outside, which allows preventingcontamination from outside.

In the method for producing a packaged drink of the present invention,besides the above effects, liquid can be feed without using pumps, inwhich small parts are difficult to sterilize, by pressure-feeding theliquid from the storage tank into the filling machine by means ofsterile gas. This facilitates sterilization of the liquid-feedingmechanism, while positive pressurization allows preventing outer airfrom intruding into the path, which allays the concern of the drinkbeing contaminated with outer air.

In the method for producing the different packaged drinks of the presentinvention, besides the above effects, hot water has also a sterilizingfunction, when used at 65° C. to 100° C. for washing the surroundingenvironment, after sterilization thereof with a chemical agent. As aresult, this allows the chemical agent to be used at a lower temperaturethan is the case in, for instance, aseptic filling, and allows curbingthereby breakdown of the chemical agent, and increasing the number oftimes that the chemical agent can be reused, while reducing damageinflicted on the equipment. The sterilizing effect againstheat-resistant spore-forming bacteria is also enhanced.

In the present invention, the surrounding environment, in whichcontainers and caps are sterilized, washed, filled and sealed, issterilized and washed beforehand using a specific chemical agent. A yetmore reliable sterilizing effect is achieved thereby.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a producing system for realizing themethod for producing a packaged drink according to an embodiment of thepresent invention.

FIG. 2 is a flowchart illustrating an embodiment of the method forproducing a packaged drink according to the present invention.

FIG. 3 is a diagram for explaining the sterilizing and washing method ofthe present invention, using a chemical agent in a clean box thatbecomes an environment-controlled space.

FIG. 4 is a flowchart illustrating another embodiment of the method forproducing a packaged drink according to the present invention.

EXPLANATION OF REFERENCE NUMERALS

-   -   1 chemical agent tank    -   3 drain tank    -   10 bottle sterilizing and washing device    -   12 capper    -   15 clean box    -   17 fixed hot water spraying nozzles    -   21 balance tank    -   23 quick cooling device    -   26 head tank    -   2 hot water tank    -   4, 5 selector valves    -   11 filling machine    -   14 environment-controlled space    -   16 rotary hot water spraying nozzles    -   20 preparation tank    -   22 high-temperature short-time sterilizer    -   25 storage tank

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention are explained below with referenceto accompanying drawings.

The drinks for which the present invention is suitable are, forinstance, green tea, Oolong tea or the like comprising 30 mg % or moreof catechins at a pH of 4.6 or higher, or acidic drinks having a pHbelow 4.6. Examples of the acidic drink include, for instance, naturaljuice, juice drinks, soft drinks containing juice, fruit drinkscontaining fruit grains, lemonade, sports drinks and the like.

The containers used in the method the present invention are, forinstance, polyester bottles such as a PET bottle, and also polyestercups, plastic containers, for instance polyester containers such astrays or the like, glass bottles, metal bottles, food cans or the like.Given that the present invention eases the conditions relating to vacuumresistance of PET bottles, the present invention is particularlysuitable for the manufacture of the above-described drinks packaged inPET bottles, in terms of reducing wall thickness.

In the method for producing a packaged drink in an embodiment of thepresent invention, the content drink is thermally sterilized, byhigh-temperature short-time sterilization, up to a predefinedsterilization value. Thereafter, the drink is immediately quick-cooleddown to room temperature (15° C. to 40° C.), and is stored in a storagetank that has been sterilized and washed beforehand under conditionsequal to or exceeding the thermal sterilization conditions of the drink.In the present invention, at least the wet surfaces of all equipment,such as the storage tank and so forth, are thermally sterilizedbeforehand, with steam or hot water, to a sterilization value equal toor higher than the sterilization value of the content drink. Also, atleast the inner face of the containers, as well as the outer surface ofthe equipment and the space environment in which containersterilization, washing, filling and sealing are carried out, arethermally sterilized and washed with hot water at 65° C. to 100° C. Thecontrolled space is herein this space environment isolated from theoutside environment. The cooled drink is stored in the storage tank,whereupon the content liquid is fed into the filling machine whilekeeping the storage tank at a positive pressure with sterile gas, tomake thereby the above-described liquid-feeding pathway into a closedliquid-feeding pathway into which outer air does not intrude. The drinkin the sterilized environment-controlled space, isolated from theoutside, is then filled at room temperature into the sterilizedcontainers, and the containers are sealed. After sealing, the containerscan move on directly, in that state, to inspection and box packing,without having to be cooled or heated.

In the case of the above-described tea drink comprising 30 mg % or moreof catechins at a pH of 4.6 or higher, the content drink, i.e. the teadrink is subjected to high-temperature short-time sterilization in sucha way so as to obtain a sterilization value equal to or higher than 135°C. and 7.58 seconds. The inventors studied the antimicrobial effectelicited by catechins vis-à-vis various microorganisms in drinkscontaining 15 mg % to 50 mg % of catechins. The results are given inTable 1. In the table, O denotes observed antimicrobial effect, Δdenotes observed or unobserved antimicrobial effect, depending onmicroorganism type, and x denotes no antimicrobial effect observed.

TABLE 1 Catechin amount (content product) 50 mg % 38 mg % 27 mg % 15 mg% Microorganism (Green tea) (Oolong tea) (Tea blend) (Tea blend)Spore-forming ∘ ∘ Δ Δ bacteria Non spore- Δ Δ Δ Δ forming bacteria Moldsx x x x Yeasts x x x x

Table 1 is shows that for tea drinks having a catechin content of 27 mg%, the antimicrobial effect was observed for most spore-formingbacteria, although the effect was weak for some spore-forming bacteria.These results indicate that, in terms of safety, the tea drinks forwhich the invention is suitable are tea drinks comprising 30 mg % ormore of catechins. For some non spore-forming bacteria, as well as moldsand yeasts, catechins exhibit no antimicrobial effect. Thesemicroorganisms can be eliminated by low-temperature heating. Theinvention affords thus an antimicrobial effect against spore-formingbacteria for tea drinks containing 30 mg % or more of catechins, andallays therefore any concerns as regards drink deterioration, regardlessof the tea drink. When the drink is the above acidic drink having a pHbelow 4.6, the drink is thermally sterilized at high temperature over ashort time so as to obtain a sterilization value equal to or greaterthan 85° C. and 30 minutes.

A typical example, in which the above drinks are filled into PETbottles, is explained below with reference to the schematic diagram of aproducing line illustrated in FIG. 1 and the flowchart illustrated inFIG. 2.

In the packaged drink production line of the present embodimentillustrated in FIG. 1, a bottle sterilizing and washing device 10, afilling machine 11, a capper 12 and a cap sterilizing and washing device(not shown) are disposed in a clean box 15 that makes up anenvironment-controlled space 14. In the present invention,“environment-controlled space” denotes a space isolated from the outsideand in which the filling and sealing equipment and the surroundingenvironment thereof have been thermally sterilized and washed beforehandwith hot water at 65° C. to 100° C. Sterile air is supplied to theinterior of the space, which is kept at a positive pressure vis-à-visthe exterior environment, in such a manner that outer air does not flowreadily into the space. Sterilization and washing of the surroundingenvironment is carried out before starting the production of thepackaged drink. As illustrated in FIG. 1, in the clean box 15 there areappropriately disposed rotary hot water spraying nozzles 16, as well asfixed hot water spraying nozzles 17 for intensively spraying hot watertowards the portions of the bottle sterilizing and washing device 10,the filling machine 11 and the capper 12 that come into contact with thecontainers. The method disclosed in Patent document 2 can beappropriately employed as the method for sterilizing and washing thesurrounding environment, and hence a detailed explanation thereof willbe omitted herein.

In the present embodiment, there are thermally sterilized at least theinner surface of the bottles fed to the bottle sterilizing and washingdevice 10 in the environment-controlled space 14 by a bottle supplydevice located outside the environment-controlled space. The innersurface of the bottles is preferably thermally sterilized with hot waterat 65° C. to 100° C. The sterilization time ranges from 3 to 10 seconds.In this method, sterilization of the bottles by hot water and subsequentwashing of the bottles are performed simultaneously, and hence there isno need for a separate washing operation of the bottles aftersterilization. Similarly, caps are supplied by a cap supply device,located outside the environment-controlled space, to a cap sterilizingand washing device disposed in the controlled space, such that the innerand outer surfaces of the caps are thermally sterilized through sprayingof hot water at 65° C. to 100° C.

The inner and outer surfaces of the bottles can be sterilized with hotwater, for instance, by placing the bottles, upside down, in a bottlewashing device, and by spraying hot water onto the bottles out of hotwater spraying nozzles. Similarly, the inner and outer faces of the capscan be sterilized with hot water by spraying hot water, from hot waterspraying nozzles, onto the inner and outer surface of the caps thatmove, for instance, through a wire chute, or that move downwards throughan opening of a turret. Once sterilized and washed, the bottles aresupplied to the filling machine 11, where they are filled with thedrink. The caps are supplied to the capper 12, and the bottles filledwith drink are capped and sealed.

As illustrated in FIG. 1, the drink, as the content liquid, is preparedin a preparation tank 20 disposed outside the clean box, is then storedin a balance tank 21, and is supplied to a high-temperature short-timesterilizer 22 and a quick cooling device 23, where high-temperatureshort-time sterilization and quick cooling are carried out.

High-temperature short-time sterilization denotes thermal sterilizationby, for instance, HTST sterilization or the like. When the drink is theabove-described tea drink comprising 30 mg % or more of catechins at apH of 4.6 or higher, high-temperature short-time sterilization iscarried out in the present embodiment in such a way so as to obtain asterilization value equal to or higher than 135° C. and 7.58 seconds.When the drink is the above acidic drink having a pH below 4.6, thedrink is thermally sterilized over a short time, for instance at 93 to95° C., so as to obtain a sterilization value equal to or greater than85° C. and 30 minutes.

The drink, having been subjected to high-temperature short-timesterilization, passes next through the quick cooling device 23, where itis subjected to quick cooling over a short time, down to roomtemperature, by heat exchange with a coolant while passing through thequick cooling device 23. Although about 35° C. is a suitable roomtemperature, the latter can range from 15° C. to 40° C. depending on,for instance, drink type, season and so forth. The drink, having beenquick cooled, is stored in a storage tank 25 comprising an aseptic tank.The storage tank 25, the quick cooling device 23, a below-described headtank 26, the filling machine 11, as well as all the wet surfaces ofpiping and so forth in contact with the foregoing, form a closed pathwaythat is sterilized beforehand through sterilization and washing withsteam or hot water in such a way so as to achieve sterilizationconditions equal to or exceeding the sterilization conditions of thedrink to be filled, i.e. sterilization conditions equal to or exceeding135° C. and 7.58 seconds. In particular, intrusion of outer air into thestorage tank 25 is prevented by keeping a positive pressure with asterile gas. Also, the stored drink is fed from the storage tank to thefilling machine, via the head tank 26, by being pressure-fed withsterile gas. As a result, liquid feeding can be achieved withoutresorting to any pumps, which are hard to sterilize and which, forstructural reasons, do not easily afford complete sterilization andsealing. Moreover, the drink can be kept in a sterile condition even atroom temperature. The head tank 26 as well is formed to be totallysealed. The drink stored in the head tank 26 is fed into the fillingmachine through pressure-feeding with sterile gas, to be filled intobottles in an aseptic environment-controlled space.

The bottles filled with the drink are conveyed from the filling machineto the capper 12, provided in the environment-controlled space, wherethe bottles are completely sealed with caps supplied from a cap supplydevice, disposed outside the environment-controlled space, andsterilized and washed under the same conditions as the bottles in thecap sterilizing and washing device disposed in theenvironment-controlled space. After being sealed, the bottles can movedirectly onwards to product inspection, box packing or the like, withouthaving to being subjected to post-processing such as post-sterilization,cooling or the like by passing through a pasteurizer and/or cooler, asin conventional hot pack methods.

FIG. 3 is a diagram for explaining the method of the present inventionfor sterilizing and washing a clean box, which becomes anenvironment-controlled space, using a chemical agent, and FIG. 4 is aflowchart of the method for producing a packaged drink according to thepresent invention. A method for producing a packaged drink in anotherembodiment of the present invention is carried out in accordance withthe steps of the flowchart of FIG. 4. In the figures, the blacktriangular arrows denote flow along the production line, while simplearrows indicate the process. In the method for producing a packageddrink in an embodiment of the present invention, the sterilizing andwashing treatment enclosed by the dot-dashed line in FIG. 4 is carriedout prior to the operation in a line 1, in which the content drink isthermally sterilized by high-temperature short-time sterilization up toa predefined sterilization value, whereafter the drink is immediatelyquick-cooled down to room temperature (15° C. to 40° C.), and is storedin a storage tank, and prior to the operation in a line 2, in which thedrink is filled and sealed into bottles. In a preliminary treatment, thequick cooling device 23, the storage tank 25 and the head tank 26 aresterilized and washed with steam or hot water under conditions equal toor exceeding the thermal sterilization conditions of the drink. Thespace environment in which container sterilization, washing, filling andsealing are carried out is a controlled space isolated from the outside.This space is sterilized with a chemical agent and washed prior to drinkfilling. Also, at least the inner surface of the used containers andcaps are thermally sterilized and washed with hot water at 65° C. to100° C. The cooled drink is stored in the storage tank, and then thecontent liquid is fed into the filling machine while keeping the storagetank at a positive pressure with sterile gas, to make thereby theabove-described liquid-feeding pathway into a closed liquid-feedingpathway (region enclosed by a broken line in FIG. 4) into which outerair does not intrude. The drink in the sterilized environment-controlledspace, isolated from the outside, is then filled at room temperatureinto the sterilized containers, and the containers are sealed. Aftersealing, the containers can move on directly, in that state, toinspection and box packing, without having to be cooled or heated.

An explanation follows next, with reference to the system diagram ofFIG. 3, on the sterilizing and washing method of the present invention,using a chemical agent in the clean box 15 as the environment-controlledspace 14. In the figure, the reference numeral 1 denotes a chemicalagent tank, 2 denotes a hot water tank, 3 denotes a drain tank, thereference numerals 4, 5 and 6 denote valves for flow path switching, 7denotes a chemical agent supply pipe, and 8 a hot water supply pipe. Theselector valves 4, 5 and 6 are initially set as illustrated in thefigure. When pressure-fed out of the chemical agent tank 1, the chemicalagent passes through the supply pipe 7 and reaches the various rotaryspraying nozzles 16 and fixed spraying nozzles 17 of the clean box 15,whereupon the chemical agent is sprayed in the clean box 15 out of therotary spraying nozzles 16 and the fixed spraying nozzles 17. Theenvironment-controlled space 14 is sterilized thus through the action ofthe sprayed chemical agent. The sprayed chemical agent flows down to thefloor, inside the chamber, and flows out of the latter via drain pipes.At this time, the selector valves 5 are in the state illustrated in thefigure, and thus the chemical agent flows towards the right in thefigure. Although the drain tank 3 is disposed on the right side, theopening/closing valve 6 is blocking herein flow into the drain tank 3,as illustrated in the figure, and hence the chemical agent isrecirculated towards the chemical agent tank 1. The chemical agentemployed is not discarded after a single use, and can be used repeatedlyas long as the sterilizing functionality thereof can be ensured. Thechemical agent is strongly acidic, and thus must be subjected to areducing treatment or pH adjustment treatment as a wastewater treatmentafter use.

Once the sterilization treatment is over, the selector valves 4 areswitched so as to shut off the chemical agent supply pipe 7 and open thehot water supply pipe 8, whereupon the selector valve 6 is set to openflow to the drain tank 3. The hot water from the hot water tank 2 passesnow through the hot water supply pipe 8 and reaches the various rotaryhot spraying nozzles 16 and fixed spraying nozzles 17 of the clean box15, whereupon the chemical agent is sprayed in the clean box 15 out ofthe rotary spraying nozzles 16 and the fixed spraying nozzles 17. Thesprayed hot water washes the chemical agent remaining in the clean box15. The hot water used for washing flows down to the floor, inside thechamber, and flows out of the latter via drain pipes. At this time, theselector valves 5 are in the state illustrated in the figure, and thusthe hot water is drained towards the right in the figure. The selectorvalve 6 blocks now flow to the chemical agent tank 1 and opens flow tothe drain tank 3, and hence the washing water flows into the drain tank3. Sterilization by chemical agent and washing of theenvironment-controlled space 14 in the clean box 15 are over after theabove operations. The selector valves 5 are then switched so as to openflow to the hot water tank 2 on the left of the figure, in preparationfor the next operation. The treatment amount of washing water and soforth in one filling and sealing operation depends on the scale of theequipment, but ranges from 2 to 3 t. In the present invention there isno large outflow of waste water, unlike in aseptic filling systems where20 t/hour of waste water are generated including container washing, andthus the waste water can be batch-treated by accumulating in the draintank 3. The environment-controlled space can be chemically sterilized byproducing lot units, or, for instance, once every 2 or 3 lots.

When using a peracetic acid agent as the chemical agent, sterilizationrequires 3 minutes at 40° C. Taking the resulting deterioration rate as1, sterilization using the chemical agent at 50° C. requires only 1minute, but to a deterioration rate of 1.5. At 60° C., sterilizationneeds only 10 seconds, to a deterioration rate of 4. That is, theincrease in decomposition rate means that less chemical agent isconserved as the number of times that the chemical agent can be re-useddecreases in proportion to the increase in the decomposition rate. Arelationship holds herein in which a higher use temperature results inan enhanced antimicrobial effect but in reduced chemical agentconservation. The antimicrobial effect of hot water is brought out when,as described above, hot water at 60° C. to 100° C. is used for washingafter using the chemical agent. Hence, chemical agent conservation canbe improved in proportion to the extent by which the usage temperatureof the chemical agent can be lowered.

At high temperatures, the chemical agent is problematic in that itdeteriorates components and inflicts damage on equipment.

In the present invention, the clean box is sterilized with a chemicalagent, and hence washing after the sterilization treatment may involvesimply washing with sterile water, without using the above-described hotwater, depending on the used chemical agent and the concentrationthereof. In this case, the selector valves 4 used must be modified intoa three-way valve that can also connect with a sterile water tank.

Also, washing may be unnecessary, depending on the chemical agent used,for instance ozone-based chemical agents.

In the present embodiment there is thermally sterilized at least theinner surface of the bottles that are fed to the bottle sterilizing andwashing device 10, in the environment-controlled space 14, by a bottlesupply device located outside the environment-controlled space. Theinner surface of the bottles is preferably thermally sterilized with hotwater at 65° C. to 100° C. The sterilization time ranges from 3 to 10seconds. In this method, sterilization of the bottles by hot water andsubsequent washing of the bottles are performed simultaneously, andhence there is no need for a separate washing operation of the bottlesafter sterilization. Rinsing with sterile water may also be carried outwith a view to washing away germs adhered to the bottles and/orpreventing deformation of lighter containers. Similarly, caps aresupplied by a cap supply device, located outside theenvironment-controlled space, to a cap sterilizing and washing devicedisposed in the controlled space, such that the inner and outer surfacesof the caps are thermally sterilized through spraying of hot water at65° C. to 100° C.

The inner and outer surfaces of the bottles can be sterilized with hotwater, for instance, by placing the bottles, upside down, in a bottlewashing device, and by spraying hot water onto the bottles out of hotwater spraying nozzles. Similarly, the inner and outer faces of the capscan be sterilized with hot water by spraying hot water, from hot waterspraying nozzles, onto the inner and outer surface of the caps thatmove, for instance, through a wire chute, or that move downwards throughan opening of a turret. Once sterilized and washed, the bottles aresupplied to the filling machine 11, where they are filled with thedrink. The caps are supplied to the capper 12, and the bottles filledwith drink are capped and sealed.

In the operation of the line 2, where the drink is filled and sealedinto the bottles, thermal sterilization is carried out by spraying hotwater onto the containers before filling. Herein, the selector valve 5from the bottle sterilizing and washing device in FIG. 3 is set towardthe left in the figure, i.e. is set to communicate with the hot watertank 2. Therefore, the process water is recirculated into the hot watertank 2, to be reused. The bottles carried in from outside into theenvironment-controlled space 14 having been sterilized beforehand withthe chemical agent are ordinarily clean. Even if some germs had becomeadhered to the bottles, the latter are subjected herein to a sterilizingand washing treatment. As a result, the process water is virtuallyuncontaminated and can hence be reused, which contributes to reducingthe amount of waste water. The caps carried in from outside are not asclean as the bottles, and hence the selector valve 5 is set toward theright in the figure, i.e. communicating with the drain tank 3, so thatthe process water from the capping chamber, in which the caps aresterilized and washed, flows into the drain tank 3, where it cannot bereused. The process amount of washing water and so forth in one fillingand sealing operation is the sum of the above chemical agent washingwater and the process water used for sterilizing and washing the caps.

As illustrated in FIG. 1, the drink, as the content liquid, is preparedin a preparation tank 20 disposed outside the clean box, is then storedin a balance tank 21, and is supplied to a high-temperature short-timesterilizer 22 and a quick cooling device 23, where high-temperatureshort-time sterilization and quick cooling are carried out.

High-temperature short-time sterilization denotes thermal sterilizationby, for instance, HTST sterilization or the like. When the drink is theabove-described tea drink comprising 30 mg % or more of catechins at apH of 4.6 or higher, high-temperature short-time sterilization iscarried out in the present embodiment in such a way so as to obtain asterilization value equal to or higher than 135° C. and 7.58 seconds.When the drink is the above acidic drink having a pH below 4.6, thedrink is thermally sterilized over a short time, for instance at 93 to95° C., so as to obtain a sterilization value equal to or greater than85° C. and 30 minutes.

The drink, having been subjected to high-temperature short-timesterilization, passes next through the quick cooling device 23, where itis subjected to quick cooling over a short time, down to roomtemperature, by heat exchange with a coolant while passing through thequick cooling device 23. Although about 35° C. is a suitable roomtemperature, the latter can range from 15° C. to 40° C. depending on,for instance, drink type, season and so forth. The drink, having beenquick cooled, is stored in a storage tank 25 comprising an aseptic tank.The storage tank 25, the quick cooling device 23, a below-described headtank 26, the filling machine 11, as well as all the wet surfaces ofpiping and so forth in contact with the foregoing, form a closed pathwaythat is sterilized beforehand through sterilization and washing withsteam or hot water in such a way so as to achieve sterilizationconditions equal to or exceeding the sterilization conditions of thedrink to be filled, i.e. sterilization conditions equal to or exceeding135° C. and 7.58 seconds. In particular, intrusion of outer air into thestorage tank 25 is prevented by keeping a positive pressure with asterile gas. Also, the stored drink is fed from the storage tank to thefilling machine, via the head tank 26, by being pressure-fed withsterile gas. As a result, feeding of liquid can be achieved withoutresorting to any pumps, which are hard to sterilize and which, forstructural reasons, do not easily afford complete sterilization andsealing. Moreover, the drink can be kept in a sterile condition even atroom temperature. The head tank 26 as well is formed to be totallysealed. The drink stored in the head tank 26 is fed into the fillingmachine through pressure-feeding with sterile gas, to be filled intobottles in an aseptic environment-controlled space.

The bottles filled with the drink are conveyed from the filling machineto the capper 12, provided in the environment-controlled space, wherethe bottles are completely sealed with caps supplied from a cap supplydevice, disposed outside the environment-controlled space, andsterilized and washed under the same conditions as the bottles in thecap sterilizing and washing device disposed in theenvironment-controlled space. After being sealed, the bottles can movedirectly onwards to product inspection, box packing or the like, withouthaving to being subjected to post-processing such as post-sterilization,cooling or the like by passing through a pasteurizer and/or cooler, asin conventional hot pack methods.

EXAMPLES Example 1

A green tea drink (pH 5.9, catechin content 52 mg %) was produced usingthe above-described equipment and producing method, employing PETbottles having a 2 L capacity.

Specifically, a green tea drink having been thermally sterilized at hightemperature for a short time, at 135° C. over 30 seconds, followed byrapid cooling to room temperature, was stored in a storage tank kept ata positive pressure with sterile gas and having been sterilized andwashed beforehand to a sterilization value equal to or greater than thesterilization value of the content. Thereafter, the drink waspressure-fed to a head tank with sterile gas, and was then supplied to afilling machine, where the drink was filled into bottles having beenthermally sterilized and washed beforehand with hot water at 90° C. for3 seconds, within a controlled space. The drink was then sealed withcaps sterilized and washed beforehand. The liquid path from the quickcooling device to the filling machine is a closed path isolated fromexternal air by being positively pressurized with sterile gas.

The pH value, hue and vitamin C of the green tea drink thus obtainedwere measured immediately after its production, in order to ascertainchanges in hue and flavor vis-à-vis green tea drinks manufactured inaccordance with a conventional hot pack method. A sensory test was alsocarried out for assessing palatability.

The results are given in Tables 2, 3 and 4.

Hue was measured in accordance with the L*a*b color specificationsystem. The L*a*b color specification system is a mixed color system inwhich the L value represents lightness, the a value represents ared-green axis and the b value a yellow-blue axis. A larger L valuedenotes a lighter color, a greater a value in the positive directionimplies stronger redness, and stronger greenness in the negativedirection, while a greater b value in the positive direction impliesstronger yellowness, and stronger blueness in the negative direction.The ΔE value is obtained by calculating the length of the straight-linedistance between two colors in the color space.

To measure vitamin C, the concentration thereof is measured afterpreparation, with the drink not yet heated. The vitamin C concentrationin the drink is measured immediately after the production thereof isover, to determine the residual ratio of the vitamin.

The sensory test was carried out based on three-point discrimination,which affords higher accuracy than two-point discrimination. Two teadrinks to be compared (A of Example 1 and B of Comparative example 1)were combined in various sets of three such as A-A-B, A-B-B and soforth. The combinations were tasted by a panel of 15 panelists, to testdiscrimination between the two drinks, and for sensory evaluation of thepalatability of the drinks.

Example 2

A 100% orange juice acidic drink (pH 3.61) was produced using theabove-described equipment and producing method, employing PET bottleshaving a 1.5 L capacity.

Specifically, the acidic drink having been thermally sterilized at hightemperature for a short time, at 94.5 to 96° C. over 30 seconds,followed by rapid cooling to room temperature (31° C. to 32° C. in thepresent example), was stored in a storage tank kept at a positivepressure with sterile gas and having been sterilized and washedbeforehand to a sterilization value equal to or greater than thesterilization value of the content. Thereafter, the acidic drink wasbottled into bottles thermally sterilized and washed with hot water at90° C. for 3 seconds, in accordance with the same method of Example 1.The filling temperature was herein 30° C. As in Example 1, immediatelyafter production of the acidic drink was over, the pH value, hue andvitamin C of the orange juice drink thus obtained were measuredimmediately after its production, in order to ascertain changes in hueand flavor of the acidic drink vis-à-vis acidic drinks manufactured inaccordance with a conventional hot pack method. The results are given inTables 5 and 6.

Comparative Example 1

In Comparative example 1, a green tea drink (pH 5.9, catechin content 52mg %) was produced using the equipment and producing method disclosed inPatent document 2, employing PET bottles having a 2 L capacity, as inExample 1. Specifically, a green tea drink having been high-temperatureshort-time sterilized at 135° C. for 30 seconds, followed by cooling to65° C., was filled and sealed into bottles sterilized and washed withhot water at 90° C. for 3 seconds, by means of a filling machine and acapper, disposed beforehand in an environment-controlled space isolatedfrom the outside by a box and having been sterilized and washed underthe same conditions as the containers. Thereafter, the PET-bottled greentea drink was cooled down to room temperature by means of a simplecooling shower, to yield a green tea drink.

The pH value, hue and vitamin C of the green tea drink thus obtainedwere measured immediately after its production was over (in this case,after cooling), in order to ascertain changes in hue and flavor, as inExample 1. The two green tea drinks were discriminated and sensorilyevaluated in accordance with a three-point discrimination method, as inthe examples. The results are given, together with those of Example 1,in Tables 2 to 4.

Comparative Example 2

In Comparative example 2, a 100% orange juice (pH3.61) was producedusing the equipment and producing method disclosed in Patent document 2,as in Comparative example 1, employing PET bottles having a 1.5 Lcapacity, as in Example 2. Specifically, an acidic drink having beenhigh-temperature short-time sterilized at 94.5 to 96° C. for 30 seconds,followed by cooling to 67 to 68° C., was filled and sealed into bottlessterilized and washed with hot water at 90° C. for 3 seconds, by meansof a filling machine and a capper, disposed beforehand in anenvironment-controlled space isolated from the outside by a box andhaving been sterilized and washed under the same conditions as thecontainers. The filling temperature was 65° C. Thereafter, thePET-bottled acidic drink was cooled down to room temperature by means ofa simple cooling shower, to yield an acidic drink.

The pH value, hue and vitamin C of the acidic drink thus obtained weremeasured immediately after its production was over (in this case, aftercooling), in order to ascertain changes in hue and flavor of the 100%orange juice, as in Example 2. The results are given, together withthose of Example 2, in Tables 5 and 6.

Evaluation of Examples and Comparative Examples Tea Drink

pH Value, Hue:

TABLE 2 pH L-value a-value b-value ΔE Prepared 6.38 90.90 −9.90 29.49Reference unheated product Example 1 6.23 89.25 −8.44 32.23 3.52 Comp.example 1 6.19 89.00 −8.14 33.88 5.10

Upon comparison, the hue of the drink in Example 1 is clearly closer tothe hue of the prepared unheated product, than is the case in the drinkof Comparative example 1, as Table 2 shows. A fresh hue can thus bepreserved in Example 1. Likewise, the pH value of the drink in Example 1can be kept closer to that of the prepared unheated product.

Vitamin C Residual Ratio:

TABLE 3 Concentration Residual (ppm) ratio (%) Prepared unheated product283 100.0 Example 1 236 83.4 Comp. example 1 215 76.0

As Table 3 shows, the residual ratio of vitamin C relative to theprepared unheated product was 83.4% in Example 1, but 76% in Comparativeexample 1. The vitamin C residual rate was clearly higher in theExample.

Palatability Sensory Evaluation:

TABLE 4 Panel of 15 Remarks Discrimination 9 panelists guessed rightSignificant difference test with 5% significance level PalatabilityAmong the 9 panelists who Drink of the Example test guessed right, 7(room-temperature preferred the drink of filling) preferred with Example1, and 2 the 5% significance level drink of Comp. example 1

As the results in Table 4 show, 9 panelists among the panel of 15 forsensory evaluation succeeded in telling apart the drinks of Example 1and Comparative example 1. Of the 9 panelists, 7 preferred the drink ofExample 1, which is indicative of the overwhelmingly better palatabilityof the drink of Example 1 vis-à-vis that of Comparative example 1.

Observation of Changes Over Time

The green tea drink bottled in 2 L PET bottles produced in Example 1 waskept at room temperature for 2 weeks, whereafter the microbial spoilageof the content was observed by visual inspection. The green tea drinkexhibited a good condition, with no microbial-spoilage turbidity beingobservable at all.

100% orange juice (acidic drink)

pH value, hue:

TABLE 5 pH L-value a-value b-value ΔE Prepared unheated 3.61 66.66 22.642.98 Reference product Example 2 3.51 65.35 23.48 42.61 1.62 Comp.example 2 3.51 64.95 24.78 42.2 2.88

Upon comparison, the hue of the drink in Example 2 is clearly closer tothe hue of the prepared unheated product, than is the case in the drinkof Comparative example 2, as Table 5 shows. A fresh hue can thus bepreserved in Example 2. That is, the 100% orange juice of Comparativeexample 2 exhibited a lower L-value (lightness), a higher a-value (red)and a lower b-value (yellow) than the drink of Example 2.

Vitamin C Residual Ratio:

TABLE 6 Concentration Residual (ppm) ratio (%) Prepared unheated product283 100.0 Example 2 270 95.4 Comp. example 2 245 86.6

As Table 6 shows, the residual ratio of vitamin C relative to theprepared unheated product was 95.4% in Example 2, but 86.6% inComparative example 2. The vitamin C residual rate was clearly higher inExample 2.

Overall Evaluation

The drinks of Examples 1 and 2 were superior to the drinks ofComparative examples 1 and 2 as regards hue measurement, pH valuemeasurement and residual ratio of vitamin C. Examples 1 and 2 allowobtaining thus drinks of excellent quality, in which the fresh hue ofthe drink can be preserved, with a high residual ratio of vitamin C.

Also, the results of the panel sensory test performed on the drinks ofExample 1 and Comparative example 1 attest the overwhelmingly higherpalatability of the drink of the Example. This bears out theeffectiveness of the method for producing a packaged drink of thepresent invention when used for packaging tea drinks and acidic drinks.

Example 3

A green tea drink (pH 5.9, catechin content 52 mg %) was produced usingthe above-described equipment and producing method, employing PETbottles having a 2 L capacity.

Specifically, the controlled space in which containers are washed,filled and sealed was sterilized beforehand at 40° C. for 10 minutesusing a peracetic acid chemical agent (trade name: Toyo Active) at aconcentration of 2000 ppm, followed by washing with hot water at 90° C.An antiseptic effect of 6 D or higher against spore-forming bacteriasuch as B. subtilis, B. coagulans was observed. Then, a green tea drinkhaving been thermally sterilized at high temperature for a short time,at 135° C. over 30 seconds, followed by rapid cooling to roomtemperature, was stored in a storage tank kept at a positive pressurewith sterile gas and having been sterilized and washed beforehand to asterilization value equal to or greater than the sterilization value ofthe content. Thereafter, the drink was pressure-fed to a head tank withsterile gas, and was then supplied to a filling machine, where the drinkwas filled into bottles having been thermally sterilized and washedbeforehand with hot water at 90° C. for 3 seconds, within a controlledspace. The drink was then sealed with caps sterilized and washedbeforehand. The liquid path from the quick cooling device to the fillingmachine is a closed path isolated from external air by being positivelypressurized with sterile gas.

The pH value, hue and vitamin C of the green tea drink thus obtainedwere measured immediately after its production, in order to ascertainchanges in hue and flavor vis-à-vis green tea drinks manufactured inaccordance with a conventional hot pack method. A sensory test was alsocarried out for assessing palatability.

The results are given in Tables 7, 8 and 9.

As before, hue was measured in accordance with the L*a*b (L-star,a-star, b-star) color specification system.

To measure vitamin C, the concentration thereof is measured afterpreparation, in an unheated state. The vitamin C concentration in thedrink is measured immediately after the production thereof is over, todetermine the residual ratio of the vitamin.

The sensory test was carried out based on three-point discrimination,which affords higher accuracy than two-point discrimination. Two teadrinks to be compared (A of Example 3 and B of Comparative example 3)were combined in various sets of three such as A-A-B, A-B-B and soforth. The combinations were tasted by a panel of 20 panelists, to testdiscrimination between the two drinks, and for sensory evaluation of thepalatability of the drinks.

Example 4

A 100% orange juice acidic drink (pH 3.61) was produced using theabove-described equipment and producing method, employing PET bottleshaving a 1.5 L capacity.

Specifically, the controlled space in which containers are washed,filled and sealed was sterilized beforehand at 40° C. for 10 minutesusing a peracetic acid chemical agent (trade name: Toyo Active) at aconcentration of 2000 ppm, followed by washing with hot water at 90° C.The acidic drink having been thermally sterilized at high temperaturefor a short time, at 94.5 to 96° C. over 30 seconds, followed by rapidcooling to room temperature (31° C. to 32° C. in the present example),was stored in a storage tank kept at a positive pressure with sterilegas and having been sterilized and washed beforehand to a sterilizationvalue equal to or greater than the sterilization value of the content.Thereafter, the acidic drink was bottled into bottles thermallysterilized and washed with hot water at 90° C. for 3 seconds, inaccordance with the same method of Example 3. The filling temperaturewas herein 30° C. As in Example 3, immediately after production of theacidic drink was over, the pH value, hue and vitamin C of the orangejuice drink thus obtained were measured immediately after itsproduction, in order to ascertain changes in hue and flavor of theacidic drink vis-à-vis acidic drinks manufactured in accordance with aconventional hot pack method. The results are given in Tables 10 and 11.

Comparative Example 3

In Comparative example 3, a green tea drink (pH 5.9, catechin content 52mg %) was produced using the equipment and producing method disclosed inPatent document 2, employing PET bottles having a 2 L capacity, as inExample 3. Specifically, a green tea drink having been high-temperatureshort-time sterilized at 135° C. for 30 seconds, followed by cooling to65° C., was filled and sealed into bottles sterilized and washed withhot water at 90° C. for 3 seconds, by means of a filling machine and acapper, disposed beforehand in an environment-controlled space isolatedfrom the outside by a box and having been sterilized and washed underthe same conditions as the containers. Thereafter, the PET-bottled greentea drink was cooled down to room temperature by means of a simplecooling shower, to yield a green tea drink.

The pH value, hue and vitamin C of the green tea drink thus obtainedwere measured immediately after its production was over (in this case,after cooling), in order to ascertain changes in hue and flavor, as inExample 3. The two green tea drinks were discriminated and sensorilyevaluated in accordance with a three-point discrimination method, as inthe examples. The results are given, together with those of Example 3,in Tables 7 to 9.

Comparative Example 4

In Comparative example 4, a 100% orange juice (pH 3.61) was producedusing the equipment and producing method disclosed in Patent document 2,as in Comparative example 1, employing PET bottles having a 1.5 Lcapacity, as in Example 4. Specifically, an acidic drink having beenhigh-temperature short-time sterilized at 94.5 to 96° C. for 30 seconds,followed by cooling to 67 to 68° C., was filled and sealed into bottlessterilized and washed with hot water at 90° C. for 3 seconds, by meansof a filling machine and a capper, disposed beforehand in anenvironment-controlled space isolated from the outside by a box andhaving been sterilized and washed under the same conditions as thecontainers. The filling temperature was 65° C. Thereafter, thePET-bottled acidic drink was cooled down to room temperature by means ofa simple cooling shower, to yield an acidic drink.

The pH value, hue and vitamin C of the acidic drink thus obtained weremeasured immediately after its production was over (in this case, aftercooling), in order to ascertain changes in hue and flavor of the 100%orange juice, as in Example 4. The results are given, together withthose of Example 4, in Tables 10 and 11.

Evaluation of Examples and Comparative Examples Tea Drink

pH Value, Hue:

TABLE 7 pH L-value a-value b-value ΔE Prepared 6.44 91.50 −10.30 30.05Reference unheated product Example 3 6.30 89.95 −8.50 33.35 3.69 Comp.example 3 6.25 88.91 −8.20 34.11 5.25

Upon comparison, as Table 7 shows, the hue of the drink in Example 3 isclearly closer to the hue of the prepared unheated product, than is thecase in the drink of Comparative example 3. A fresh hue can thus bepreserved in Example 3. Likewise, the pH value of the drink in Example 3can be kept closer to that of the prepared unheated product.

Vitamin C Residual Ratio:

TABLE 8 Concentration Residual (ppm) ratio (%) Prepared unheated product305 100.0 Example 3 260 85.2 Comp. example 3 236 77.4

As Table 8 shows, the residual ratio of vitamin C relative to theprepared unheated product was 85.2% in Example 3, but 77.4% inComparative example 3. The vitamin C residual rate was clearly higher inthe Example.

Palatability Sensory Evaluation:

TABLE 9 Panel of 20 Remarks Discrimination 12 panelists guessed rightSignificant difference test with 5% significance level PalatabilityAmong the 12 panelists Drink of the Example test who guessed right, 8(room- temperature preferred the drink of filling) preferred withExample 3, and 4 the 5% significance level drink of Comp. example 3

As the results in Table 9 show, 12 panelists among the panel of 20 forsensory evaluation succeeded in telling apart the drinks of the Exampleand the Comparative example. Of the 12 panelists, 8 preferred the drinkof Example 3, which is indicative of the overwhelmingly betterpalatability of the drink of Example 3 vis-à-vis that of Comparativeexample 3.

Observation of Changes Over Time

The green tea drink bottled in 2 L PET bottles produced in Example 3 waskept at room temperature for 2 weeks, whereafter the microbial spoilageof the content was observed by visual inspection. The green tea drinkexhibited a good condition, with no microbial-spoilage turbidity beingobservable at all.

100% orange juice (acidic drink)

pH value, hue:

TABLE 10 pH L-value a-value b-value ΔE Prepared unheated 3.55 67.6122.00 43.32 Reference product Example 4 3.46 65.90 24.10 43.01 2.73Comp. example 4 3.46 65.03 25.04 42.60 4.05

Upon comparison, as Table 10 shows, the hue of the drink in Example 4 isclearly closer to the hue of the prepared unheated product, than is thecase in the drink of Comparative example 4. A fresh hue can thus bepreserved in Example 4. That is, the 100% orange juice of Comparativeexample 4 exhibited a lower L-value (lightness), a higher a-value (red)and a lower b-value (yellow) than the drink of Example 4.

Vitamin C Residual Ratio:

TABLE 11 Concentration Residual (ppm) ratio (%) Prepared unheatedproduct 320 100.0 Example 4 295 92.2 Comp. example 4 276 86.3

As Table 11 shows, the residual ratio of vitamin C relative to theprepared unheated product was 92.2% in Example 4, but 86.3% inComparative example 4. The vitamin C residual rate was clearly higher inExample 4.

Overall Evaluation

The drinks of Examples 3 and 4 were superior to the drinks ofComparative examples 3 and 4 as regards hue measurement, pH valuemeasurement and residual ratio of vitamin C. Examples 3 and 4 allowobtaining thus drinks of excellent quality, in which the fresh hue ofthe drink can be preserved, with a high residual ratio of vitamin C.

Also, the results of the panel sensory test performed on the drinks ofExample 3 and Comparative example 3 attest the overwhelmingly higherpalatability of the drink of the Example. This bears out theeffectiveness of the method for producing a packaged drink of thepresent invention when used for packaging tea drinks and acidic drinks.

INDUSTRIAL APPLICABILITY

The method for producing a packaged drink of the present invention canbe appropriately used for producing packaged drinks of non-nutritionallyenriched drinks in which growth of spore-forming bacteria is difficultafter heating, for instance, drinks such as green tea, Oolong tea or thelike comprising 30 mg % or more of catechins at a pH of 4.6 or higher,acidic drinks of pH lower than 4.6, mineral water or the like. Thecontainers are not limited to synthetic resin bottles such as PETbottles or the like. The invention can also be used for other containertypes such as metal bottles, metal cans, glass bottles or the like.

1. A method for producing a packaged drink, comprising the steps of:thermally sterilizing and washing beforehand, using hot water at 65° C.to 100° C. or a chemical agent, a surrounding environment where acontainer and a cap are sterilized, washed, filled and sealed; thermallysterilizing and washing beforehand a liquid-feeding pathway, up to acooling device, a storage tank and a filling machine, under conditionsequal to or exceeding the thermal sterilization conditions of a drink tobe filled; and thermally sterilizing and washing at least an innersurface of the container and cap with hot water at 65° C. to 100° C.,wherein the drink to be filled is thermally sterilized up to apredetermined sterilization value and is thereafter quickly cooled toroom temperature, the cooled drink being stored in the storage tank, andwherein a content liquid is fed to the filling machine to make theliquid-feeding pathway into a closed liquid-feeding pathway into whichouter air does not intrude, and the surrounding environment is made anenvironment-controlled space isolated from the outside, such that thedrink is filled at room temperature into the sterilized container andthen sealed in the environment-controlled space.
 2. The method forproducing a packaged drink according to claim 1, wherein the drink is adrink comprising 30 mg % or more of catechins at a pH of 4.6 or higher,and the drink is thermally sterilized to a sterilization value equal toor higher than 135° C. and 7.58 seconds.
 3. The method for producing apackaged drink according to claim 1, wherein the drink is an acidicdrink having a pH below 4.6, and the acidic drink is thermallysterilized to a sterilization value equal to or higher than 85° C. and30 minutes.
 4. The method for producing a packaged drink according toclaim 1, wherein the environment-controlled space is a space housed in abox.
 5. The method for producing a packaged drink according to claim 1,wherein the storage tank is kept at positive pressure with sterile gas,and the liquid is fed from the storage tank to the filling machinethrough pressure-feeding by sterile gas.
 6. The method for producing apackaged drink according to claim 1, wherein washing which is performedafter thermal sterilization and washing of the surrounding environmentusing a chemical agent has also a sterilizing function by using hotwater at 65° C. to 100° C.
 7. The method for producing a packaged drinkaccording to claim 1, wherein any of a peracetic acid chemical agent,hydrogen peroxide, an ozone-based chemical agent, and a chlorine-baseddisinfectant containing hypochlorous acid is used as the chemical agentfor sterilizing and washing beforehand the surrounding environment wherea container and a cap are sterilized, washed, filled and sealed.